Voice packet communications system with communications quality evaluation function

A voice packet communication system, comprising:

• an encoding means for producing voice packets using voice information, producing reference voice packets using said voice information, transmitting said voice packets using a first protocol of which a communication quality is not guaranteed, and transmitting said reference voice packets using a second protocol of which a communication quality is guaranteed;
• a decoding means for converting said voice packets into voice information and converting said reference voice packets into reference voice information;
• and
• a judgment means for judging the communication quality of said voice packets by comparing said voice information with said reference voice information;
• wherein said encoding means is installed inside a packet transmitting device that transmits said voice packets and said reference voice packets, and said decoding means and said judgment means are installed inside a packet receiving device.